Search results for "Phosphoric acid"
showing 6 items of 86 documents
Contributions to the application of the transferability principle and the multipolar modeling of H atoms: electron-density study of L-histidinium dih…
2006
The electron density of L-histidinium dihydrogen orthophosphate orthophosphoric acid has been determined from X-ray and neutron diffraction data at low temperature (120 K). Topological analysis of the electron density has been used to analyse the effect of the multipolar refinement strategy on the electron-density model in the hydrogen-bonding regions. The electron density at low temperature has also been used to acquire high-quality experimental thermal parameters at room temperature using the transferability principle. Molecular vibrations, TLS and normal mode analysis are discussed and studied at both temperatures.
Darstellung eines reinen monomeren formaldehyds durch acidolytische depolymerisation von Trioxan. 22. Mitt. über polyoxymethylene1
1964
Trioxan wird mit nahezu quantitativem Umsatz kontinuierlich in einem Stickstoffstrom bei 200°C an einem Pyrophosphorsaure-Kontakt zu monomerem Formaldehyd depolymerisiert. Durch Vorpolymerisation von ca. 5% des gasformigen Formaldehyds werden die geringfugigen Verunreinigungen wie Methylformiat, Wasser und unumgesetztes Trioxan entfernt, so das das restliche Monomere eine Reinheit von mindestens 99,98% besitzt. Losungen dieses Formaldehyds in Toluol oder Diathylather zeigen zwischen –78 und –50°C eine sehr gute Haltbarkeit. Trioxane is depolymerized almost quantitatively to form monomeric formaldehyde in a flow system at 200°C. using pyrophosphoric acid as catalyst and nitrogen as a carrier…
Pharmakologisch aktive polymere, 8.Poly[2-(methylsulfinyl)äthylacrylat]e und ihre vermittelnde wirkung auf die transkutane resorption von pharmaka
1975
Poly[2-(methylsulfinyl)athylacrylat] (2a) und Poly[2-(methylsulfinyl)athylmethacrylat] (2b) wurden synthetisiert und auf ihre vermittelnde Wirkung bei transkutaner Resorption einiger Pharmaka untersucht. 2b verbesserte die Resorption der Phosphorsaureester Dimethoat® und Paraoxon® und der p-Aminohippursaure und war etwa mit der Wirksamkeit von DMSO vergleichbar. Ein geringer penetrationsfordernder Effekt ergab sich fur Dinitrochlorbenzol. Nicht beeinflust wurde die dermale Resorption von Isoprenalinsulfat. Die beiden Polymeren zeigten eine gute Lokalvertraglichkeit und 2b auch keine akute Allgemeintoxizitat bei systematischer Anwendung. Der fur DMSO charakteristische knoblauchartige Geruch …
Green approach to corrosion inhibition of stainless steel in phosphoric acid of Artemesia herba albamedium using plant extract
2019
Essential oil from aerial parts of Artemisia herba-alba from Morocco was hydrodistilled and its chemical composition oil was investigated by capillary GC and GC/MS. The major components were 1,8-cineole (35.6%) and camphor (24.1%). Artemisia herba-alba essential oil AHAO was tested as corrosion inhibitor of stainless steel (SS) in 1M H3PO4 using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy measurements (EIS) and scanning electronically microscopy (SEM) studies. The results obtained showed that the essential oil of Artemisia reduces the corrosion rate. Tafel polarization method indicates that the plant extract behaves as a mixed type inhibitor. The inhibition…
Cytotoxic effects of two acid solutions and 2.5% sodium hypochlorite used in endodontic therapy
2010
Aim: To evaluate the cytotoxicity of 15% citric acid, 5% phosphoric acid and 2.5% NaOCl on cultured fibroblasts using MTT colorimetric assay. Methodology: Irrigating solutions of 5% phosphoric acid, 15% citric acid, and 2.5% NaOCl, diluted at 0.1% and 0.5%, were applied to cell cultures of 3T3L1 fibroblasts. The cell viability was determined by means of MTT colorimetric assay after a period of 1, 6 and 24 hours. Percentages of cell viability were analyzed using the Kruskal-Wallis test for global comparisons and the Mann-Whitney U-test for pairwise comparisons. Results: The percentage of cell viability diminished progressively over a 24 hour period in all solutions at both dilutions. At 0.1%…
Preparation of tungstophosphoric acid/cerium-doped NH2-UiO-66 Z-scheme photocatalyst: a new candidate for green photo-oxidation of dibenzothiophene a…
2021
International audience; The goal of this study was to introduce an effective visible-light induced photocatalytic system with a good ability for photocatalytic oxidative desulfurization (PODS) and denitrogenation (PODN) using molecular oxygen (O2) as an oxidant. In this regard, tungestophosphoric acid (PW12) was supported onto cerium-doped NH2-UiO-66 (PW12/Ce-NUiO-66) and employed for the photo-oxidation of dibenzothiophene (DBT) and quinoline (Qu). Herein, using cerium (Ce) as a “mediator” facilitated the separation of charge carriers, while NH2-UiO-66 remarkably enhanced the surface area with plentiful adsorption sites and shifted the adsorption edge of PW12to the visible region. The sum …